Derbj 4?4: [May 10, 



etc. The most interesting is a boulder of metamorphosed conglomerate, 

 containing rounded pebbles, the size of one's list, of the rocks above men 

 tioned, united by a metamorphosed, silicious cement. These boulders un- 

 doubtedly indicate the neighborhood of some high point of the original 

 surface of the underlying metamorphic rocks, which, before being buried, 

 formed an island in the sen, in which the deposits of shale and sandstone 

 were being laid down. 



In the portions of this region where the sandstone is the prevailing sur- 

 face rock, the soil is poor and sandy, supporting only grasses and, on the 

 slopes, small patches of forest, in which the Araucarian pine occurs in great 

 abundance. This tree is also extremely abundant on the metamorphic 

 plateau of Curityba. The shaly portions of the region have a somewhat 

 better soil, but are still poor, in the eastern and central parts. Going west- 

 ward, the soil improves, the beautiful open campos giving place to others 

 with scattered pines and an abundance of shrubs, and these in turn, in the 

 extreme west, where the shale is more varied in character, and where 

 diorite and calcareous rocks are abundant, are replaced by luxuriant forests, 

 showing the superior quality of the soil. 



The geological age of this sandstone and shale has never been satisfac- 

 torily determined. The first light on the subject was thrown by a few 

 fragmentary fossils, discovered by Mr. Luther Wagoner, Assistant of the 

 Geological Commission, in 1870, and determined by Mr. Rathbun and my- 

 self to be Palaeozoic, and probably Devonian. A few months ago, I found 

 in the province of Sao Paulo, in a cherty limestone, identical with that 

 above mentioned, a few obscure Lamellibranchs, belonging to Devonian 

 or Carboniferous types. In my last excursion I visited the localities dis- 

 covered by Mr. Wagoner, and had the good fortune to find more perfect 

 specimens. From a bed of shale, intercallated in the sandstone, at Ponta 

 Grossa, close by the conglomerate locality above mentioned. I found a 

 species of Ophiuran, a few badly preserved Lamellibranchs, and species of 

 Lingula, Distinct,, Spirifera, Rhynchonelln, Streptorhynchus and Vitulinn, 

 strongly resembling, and probably identical with, those of the Devonian 

 of the Amazonas. The Spirifera, Streptorhynchus and Vitulina are par- 

 ticularly well-marked Devonian types, the former being probably identical 

 with S. duodenaria. In the cherty limestone at Ivahy, I found a number 

 of species of Lamellibranchs, some of which arc identical with those of 

 Sao Paulo, but I could not, in the field, give them the study required to 

 determine with certainty whether they belong to the Devonian or Car- 

 boniferous. Fragments of Lepidodendron also occur in the same rocks. 



As above remarked, the elevation of this second region diminishes some- 

 what towards the west, where the heights, including the diorite ridges, 

 rise to 850 or 900 metres, although, owing to the excessive deepening and 

 widening of the numerous valleys, the general level is somewhat lower. 

 From this level rises a second escarpment, known as the Serrade Esperancu, 

 to a height of 1040 metres. On the steep slope there is seen, in ascend- 

 ing, a considerable thickness of soft, red sandstone, overlying the shales 



